Influence of Context on Item Parameters in Forced-Choice Personality Assessments

A fundamental assumption in computerized adaptive testing (CAT) is that item parameters are invariant with respect to context – items surrounding the administered item. This assumption, however, may not hold in forced-choice (FC) assessments, where explicit comparisons are made between items included in the same block. We empirically examined the influence of context on item parameters by comparing parameter estimates from two FC instruments. The first instrument was compiled of blocks of three items, whereas in the second, the context was manipulated by adding one item to each block, resulting in blocks of four. The item parameter estimates were highly similar. However, a small number of significant deviations were observed, confirming the importance of context when designing adaptive FC assessments. Two patterns of such deviations were identified, and methods to reduce their occurrences in a FC CAT setting were proposed. It was shown that with a small proportion of violations of the parameter invariance assumption, score estimation remained stable

On the identity and typification of Solanum brasilianum Dunal (Solanaceae)

The file attached is the published version of the article.NHM Repositor

Structured Discussion and Early Failure Prediction in Feature Requests

Feature request management systems are popular tools for gathering and negotiating stakeholders' change requests during system evolution. While these frameworks encourage stakeholder participation in distributed software development, their lack of structure also raises challenges. We present a study of requirements defects and failures in large scale feature request management systems, which we build upon to propose and evaluate two distinct solutions for key challenges in feature requests. The discussion forums on which feature request management systems are based make it difficult for developers to understand stakeholders' real needs. We propose a tool-supported argumentation framework, DoArgue, that integrates into feature request management systems allowing stakeholders to annotate comments on whether a suggested feature should be implemented. DoArgue aims to help stakeholders provide input into requirements activity that is more effective and understandable to developers. A case study evaluation suggests that DoArgue encapsulates the key discussion concepts on implementing a feature, and requires little additional effort to use. Therefore it could be adopted to clarify the complexities of requirements discussions in distributed settings. Deciding how much upfront requirements analysis to perform on feature requests is another important challenge: too little may result in inadequate functionalities being developed, costly changes, and wasted development effort; too much is a waste of time and resources. We propose an automated tool-supported framework for predicting failures early in a feature request's life-cycle when a decision is made on whether to implement it. A cost-benefit model assesses the value of conducting additional requirements analysis on a body of feature requests predicted to fail. An evaluation on six large-scale projects shows that prediction models provide more value than the best baseline predictors for many failure types. This suggests that failure prediction during requirements elicitation is a promising approach for localising, guiding, and deciding how much requirements analysis to conduct

Il tempo della ricerca. Comprendere la scienza per superare l'emergenza COVID-19

La pandemia da COVID-19 ha determinato una situazione di emergenza senza precedenti nell'ultimo secolo a livello globale1. Secondo le stime, alla fine del 2020 si conteranno purtroppo quasi 100 milioni di casi e oltre 2 milioni di morti dall'inizio della pandemia2.Nonostante la mortalità inferiore rispetto ad altri virus, la capacità del COVID-19 di diffondersi molto rapidamente ha posto sotto pressione i sistemi sanitari di molti Paesi, tra cui l'Italia, come mai era avvenuto prima nella storia recente, portando in alcuni casi alla saturazione delle capacità di assistenza. A sua volta, la crisi sanitaria, caratterizzata da ondate epidemiche di proporzioni sempre maggiori, ha comportato gravi ripercussioni a livello socio-economico il cui impatto risulta ancora difficile da prevedere in tutta la drammaticità

Chief Executives Board for Coordination (CEB) Communique

Announcing the United Nations System Chief Executives agreement to nine joint initiatives in response to the crisis

Micromechanical modeling of tension stiffening in FRP-strengthened concrete elements

This article presents a micromodeling computational framework for simulating the tensile response and tension-stiffening behavior of fiber reinforced polymer–strengthened reinforced concrete elements. The total response of strengthened elements is computed based on the local stress transfer mechanisms at the crack plane including concrete bridging stress, reinforcing bars stress, FRP stress, and the bond stresses at the bars-to-concrete and fiber reinforced polymer-to-concrete interfaces. The developed model provides the possibility of calculating the average response of fiber reinforced polymer, reinforcing bars, and concrete as well as the crack spacing and crack widths. The model, after validation with experimental results, is used for a systematic parameter study and development of micromechanics-based relations for calculating the crack spacing, fiber reinforced polymer critical ratio, debonding strength, and effective bond length. Constitutive models are also proposed for concrete tension stiffening and average response of steel reinforcing bars in fiber reinforced polymer–strengthened members as the main inputs of smeared crack modeling approaches

Broiler breeder behavior and egg production as function of environmental temperature

916Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Chaos in Anisotropic Pre-Inflationary Universes

We study the dynamics of anisotropic Bianchi type-IX models with matter and cosmological constant. The models can be thought as describing the role of anisotropy in the early stages of inflation. The concurrence of the cosmological constant and anisotropy are sufficient to produce a chaotic dynamics in the gravitational degrees of freedom, connected to the presence of a critical point of saddle-center type in the phase space of the system. The invariant character of chaos is guaranteed by the topology of the cylinders emanating from unstable periodic orbits in the neighborhood of the saddle-center. We discuss a possible mechanism for amplification of specific wavelengths of inhomogeneous fluctuations in the models. A geometrical interpretation is given for Wald's inequality in terms of invariant tori and their destruction by increasing values of the cosmological constant.Comment: 14 pages, figures available under request. submitted to Physical Review

Pull-out and push-in tests of bonded steel strands

Martí Vargas, JR. (2013). Pull-out and push-in tests of bonded steel strands. Magazine of Concrete Research. 65(18):1128-1131. doi:10.1680/macr.13.00061S112811316518Balázs LG .Bond Model with Non-Linear Bond-Slip Law, 1987, Politecnico di Milano, Italy, 395–430, Studi e Ricerche, Post-Graduate Course for Reinforced Concrete Structures, V.8/86.Balazs, G. L. (1992). Transfer Control of Prestressing Strands. PCI Journal, 37(6), 60-71. doi:10.15554/pcij.11011992.60.71Balazs, G. L. (1993). Transfer Length of Prestressing Strand as a Function of Draw-In and Initial Prestress. PCI Journal, 38(2), 86-93. doi:10.15554/pcij.03011993.86.93Balázs, G. L. (2007). Connecting Reinforcement to Concrete by Bond. Beton- und Stahlbetonbau, 102(S1), 46-50. doi:10.1002/best.200710109Carmo RNF .Ancoragem de Armaduras Pré-Esforçadas por Pré-Tensão. MSc thesis, 1999, Faculdade de Ciências e Tecnologia, Universidade de Coimbra, Portugal, (in Portuguese).Faria, D. M. V., Lúcio, V. J. G., & Pinho Ramos, A. (2011). Pull-out and push-in tests of bonded steel strands. Magazine of Concrete Research, 63(9), 689-705. doi:10.1680/macr.2011.63.9.689Faria, D. M. V., Lúcio, V. J. G., & Ramos, A. P. (2011). Strengthening of flat slabs with post-tensioning using anchorages by bonding. Engineering Structures, 33(6), 2025-2043. doi:10.1016/j.engstruct.2011.02.039Faria, D. M. V., Lúcio, V. J. G., & Pinho Ramos, A. (2012). Post-punching behaviour of flat slabs strengthened with a new technique using post-tensioning. Engineering Structures, 40, 383-397. doi:10.1016/j.engstruct.2012.03.014Laldji S .Bond Characteristics of Prestressing Strand in Grout. MPhil thesis, 1987, University of Leicester, UK.Laldji, S., & Young, A. G. (1988). Bond between steel strand and cement grout in ground anchorages. Magazine of Concrete Research, 40(143), 90-98. doi:10.1680/macr.1988.40.143.90Lopes, S. M. R., & do Carmo, R. N. F. (2002). Bond of prestressed strands to concrete: transfer rate and relationship between transmission length and tendon draw-in. Structural Concrete, 3(3), 117-126. doi:10.1680/stco.2002.3.3.117Martí-Vargas, J. R., Serna-Ros, P., Fernández-Prada, M. A., Miguel-Sosa, P. F., & Arbeláez, C. A. (2006). Test method for determination of the transmission and anchorage lengths in prestressed reinforcement. Magazine of Concrete Research, 58(1), 21-29. doi:10.1680/macr.2006.58.1.21Marti-Vargas, J. R., Arbelaez, C. A., Serna-Ros, P., Navarro-Gregori, J., & Pallares-Rubio, L. (2007). Analytical model for transfer length prediction of 13 mm prestressing strand. Structural Engineering and Mechanics, 26(2), 211-229. doi:10.12989/sem.2007.26.2.211Palmer, K. D., & Schultz, A. E. (2011). Experimental investigation of the web-shear strength of deep hollow-core units. PCI Journal, 56(4), 83-104. doi:10.15554/pcij.09012011.83.10